Reversed-acting intermediate relay



Aug. 27, 1929. C A, QTTO 1,726,409

REVERSED ACTING INTERMEDIATE RELAY Filed Nov. 8, 192g Kw1 as Patented Aug. 27, `1929.

UNI-TED *srarlszs 1,726,409 PATENT OFFICE.

CARI. n. erro, OFJMILWAUKEE, WISCONSIN, vASSIefNOnfro JOHNSON SERVICE COM- rANY, or MILWAUKEE, WISCONSIN, A CORPORATION OF WISCONSIN.

REVERSED-ACTIN G INTERMEDIATE g Application med. November s', 1192s.` sriarivo. zzl'arrzt,y

controlled chamber follows closely a pres sure established in a controlling chamber 'as Vthel resulto-fv the varying 'indications` of a responsive element such .as abi-metallic then mostatic/ bar. f

` The present invention provides an instrumentin `which pressure in the controlled chamber r varies i inversely with reference to V. variations of lpressure inthe controlling Ato chamber, the variations of pressurer in, the 4controlling chamber -being produced, as before, by the actionof, a responsive element. r The instrument forming the subject Inatter of the present application is applicable generally,rbut it lderives peculiar utility in those installations where it is desired to use two relays operating .in reverse senseswhen ,controlledl by' av singlefresponsive element. yThe structurevherein claimed-preserves, as far as is reasonably possible,\the structural characteristics of .the `Otto and Otto device. In the drawings, A

i Fig.`1 isa front yelevation of theqdevice showing this connected to a radiator valve lwhich is illustrated merely as ar typical .mechanism controllable bythe thermostat. FFiga '2 is a section on the .line 2-2 of f1g.1.

Y The body of the deviceis illustrated at. 5 and is intended to bemounted on the usual pipe head, not shown, by which theusual connections to the supply'l and control ipe are made. Pressure fluid is supplied rom the pipe head to arecess 6. l A second recess 7, shown in dotted, lines Fig.. 1, is connected by apipe 8 with a shell 9 of the ral,diator valve.Y motor. This motor consists of ametallic bellows 11 upon the to'pr of which the fluid pressure acts. `4Mounted in thetop of the bellows .11 is a pressure plate 12 connectedto the valve stem` 13 which isl sur rounded by thrust spring 10. The valve stem passes through gland `14 andv is c011- nected at endlto the radiator valve 15.

.trolledy chamber.

Triis coacts with a seat 16 in the'valve body It will be observed that ,whenl pipe 8 is vented the spring l0 closes the valve 15.

Pressure fluid supplied tov ythe casing 9 throughthe pipe 8 will act pupon the bellows `11, overpower the spring 10 and open .the valve 15. As stated, the radiator valve mechanism is merely typical ofthe device .to bel operated.

`liormed inthe front face of the body 5 is a recess or chamber 21, which is the con-V The forward side ofthis chamber is coveredby a" ilexible, diaphragm l 22.V This diaphragm is heldin place .by a l clamping ring 24-V which in turn supports a secondlexible diaphragml 25. vThe ring 24 is shouldered or 4counterboreol, as shown,

so that .the effective area of the diaphragm 25 is greaterthan the eifectivearea of the diaphragm-22. The space 26 between the two diaphragms is the controlling chamber. The diaphragm25 is` held in place by a tlanged coverplate 27 which together with the ring 24is heldin place by the machine screws 28. u v

, The space betweeny the diaphragm 25 and'` cover' 27 `is vented to atmosphere kat 29` so that in effect the diaphragm 25 is subject to y, e

atmospheric pressure at all times on' its vouter or forward face. p 31 extends through alined central apertures 4in the diaphragms 224 and 25. A reinforcing late 32and nut 33 clamp the member 31 to t e diaphragm 22 and a nut` 34 clamps it to the front diaphragm 25.

, A thrust plate 35 encircles the nut 34 and acts as a seat for the coil spring 36 which reacts between the cover 27 and the thrust plate 35 to urge both diaphragms and their central connecting piece 31 inward, or to .the left relatively to Fig. l2. The recess communicates by means of a passage' 37 with a chamber 38 into which is threaded `,from theba'ck of the` body 5, a plug'39.

Plug 39 is formed with an annular spring seat 41 vwhich receives a spring 42 and thisV ksp1-ing` reacts 1n a closing direction againsta A tubular member conical valve 43. The valve 43 is guided in kthe plug 39 by means of a pilot or stem 44. The valve.` 43 seats at 45 in a passage leadmg from the chamber 38 to the controlled chamber 21., It is axially alined with the bore 46 of the tubular member 31;.

and thusv leads from the chamber 21 to the space between diaphragm 25 and the cover 27, which, as explained, is always open to atmosphere. i

When themember 31 moves to the left 1t engages the valve 43 so that this valve closes the passage 46. Continued motion of the member 31 to the lett has the eilect of lifting i the valve 43 from the seat 45 to admit pressure through the passage 37 to the-controlledp y chamber 21.

4plug screw '49.V

' the controlling chamber 26 there leads a pasvsage 55 which extends to a recess 56 in the body 5. The recess 56 is connected lthrough the pipe head to a leak port 57 lwhich is controlled by the valve member 58 on the end of the bi-metallic thermostatic bar 59. This bar is supported at its lowerr end in any l known manner, for example', in the manner shown in Patent 1,500,260, and is merely representative of any responsive element such as a thermostat, hygrostat and the like.

The needle valve 52-is so adjusted that the flow past the needle valve is decidedly less than the capacity of the leak port 57. It

follows that'the gradual opening'and closing of the leak port 57 produces gradual changes of pressure in the controlling chamber 26.

The controlled chamber 21 is connected by y Athe passage 61 with the recess 7 and conseuently with the pipe 8. The strength of t e spring 36 is properly chosen with reference to the pressures to be used and the areas of the diaphragms 22 and 25.

In operationair under pressure will be supplied by the pipe head to the recess 6. Air flowing by way of passage 51 to the controlling chamber will establish in that chamber a pressure which varies with the variable opening of the leak port 57. This variable opening is controlledby the thermostatically actuated valve 58. As the pressure in the controlling chamber 26 rises the two diaphragms act in opposition to each other and the larger diaphragm prevails softhat the diaphragms move forward or to the right as seen in Fig. 2.. The eifect of this is to cause valve 43 to seat at 45, cutting off the suplply and at the same time to open the ex aust portv46. Thus the pressure in the controlled chamber drops as the pressure in the controlling chamber rises. Conversely a reduction of pressure in the controlling rThat is claimed is,+

The motion of the .diaphragms 22 and 25 is gradual and the changes of pressure which occur in the chamber 21 as the result of changes of pressure in the chamber 26 exert a corrective or limiting action on the motion of the diaphragm 22. Consequently the controlled pressure varies progressively withv the lchanges of pressure in the controlling chamber but in the `reverse sense.

This reverse acting progressive relay is of general applicability but is of particular utility in cases where the relay structure of the present'application and the relay structure of Patent 1,500,260, areconjointly controlled by a single thermostatic bar. Obviously,` a single such bar and leak port could be connected to the controlling chamber 18 of the issuedrpa'tent and to the controlling chamber 26 of the present application, and

control the two simultaneously'. In such cases the relays would operate in reverse senses. It `often happens-that two such diverse mechanisms produce a simple installation adaptablertomany `circumstances encountered in theV automatic control art as will `readily be appreciated. r

While the device has beenl described with some particularity itymay be embodied in somewhat different forms within the scope of the invention.`

V1. A control device comprising in combination two spaceddiaphragms `of'difterent areas; a casing, forming with the diaphragms a controlling chamber' between the diaphragms in which pressure acts oppositely in the `two diaphragms, and a controlled chamber 1n which pressure acts against the smaller diaphragm, said controlled chamber being arranged for connection to a device to be controlled; a member connecting said diaphragms to move in unison; a valve controlling the Supply of pressure Huid yto the controlled chamber andthe exhaust of iuid therefrom and arranged to open supplyand exhaust alternately with an intermediate position in which both are closed; connections for actuatingsaid Valve by the motion of said diaphragms; yielding means urging said diaphragms in a direction to open the supply; and means responsive to atmospheric conditions for varying the pressure in said controlling chamber. .y

nation ay body having an open sided chamber; a pressure fluid supply passage Yleading to said chamber, and a, passage for connecting said chamber' with a device to be'con- 2. A control device comprising in combil y tro'iied; a diaphragm closing the open side of said chamber; a second and largerdiaphragm enclosing between it and the first diaphragm a second chamber, the second diaphragm being subject on its outer side to atmospheric pressure; a member connecting said diaphragms andhaving an exhaust passage leading from the first chamber to atmosphere; a valve controlling said supply passage, yieldingly urged in a closing direction, arranged to be engaged by said connecting member as the diaphragms move inward, and when so engaged to close the exhaust passage and upon urthermovement to open said supply passage; valve means responsive to atmospheric conditions to vary thepressure in said second chamber; and yielding means urging said diaphragms inward. i

In testimony whereof I have signed my 20 

